Variable-speed-transmitting device.



. PATENTED MAR. 19, 1907; E. RICHTER. VARIABLE SPEED TRANSMITTING DEVICE.

APPLIOATION FILED APR.17. 1905.

annex rim:

. Witnesses M0 WW ERNST RICHTER, OF CINCINNATI, OHIO.

VARIABLE-SPEED-TRANSMITTING DEVICE.

v Specification of Letters'Patent.

Patented March 19, 1907.

Application filed April 17, 1905. Serial No. 265,935.

To all whom it may concern:

Be it known that I, ERNST RICHTER, a citizen of the United States ofAmerica, and a resident of Cincinnati, in the county of Hamilton andState of Ohio, have invented certain new and useful Improvements inVariable Speed Transmitting Devices, of which the following is aspecificatit'in.-

This invention relates to certain improvements in variable-speed-transmitting devices, and particularly in that class of such deviceswherein are employed oppositely-arranged conoidal pulleys around whichis passed a band or belt capable of movement in the direction of thelength of said pulleys, so that by such movement of the band or belt oneof said pulleys may be driven at different speeds from the other; andthe object of the invention is to provide a transmitting device of thisgeneral character wherein the band or belt is afforded a greater are ofcontact or extent of bearing around the circumference of the pulleys, sothat narrower belts or bands may be employed without lessening ofefficiency and wherein are provided improved means for preventing suchband or belt from creeping during the operation of the transmittingmechanism lengthwise along the pulleys, whereby this defect, which ispresent in this description of transmitting devices as ordinarilyconstructed, is altogether avoided.

The invention consists in certain novel features of the construction,combination, and arrangement of the several parts of the improvedtransmitting device whereby certain important advantages are attained,all as will be hereinafter fully set forth.

The novel features of the invention will be carefully defined in theclaims.

In the accompanying drawings, which serve to illustrate my invention,Figure 1 is a side elevation of an improved transmitting deviceconstructed according to my invention, and Fig. 2 is a transversesection taken through the same in the plane indicated by line a a inFig. 1. Fig. 3 is a sectional detail view showing the shifting orintermediate.

sheave or pulley detached. Fig. 4 is a vertical sectional View showingthe construction and arrangement of the intermediate or shifting pulleyorsheave and its supporting means as constructed according to a modifiedform of the device.

Referring first to Figs. 1, 2, and 3, 1 l indicate theoppositely-located arms or portions of a bearing-frame of any desiredkind, and which have alined bearings2 2 at opposite ends, said arms orframe portions 1 1 being spaced apart, so that said bearings 2 2 mayreceive the op osite ends of shafts 3 3, which are parallel w1th eachother and whereon are secured the respective oppositelyarrangedcone-pulleys 4 and 5, the arrangement of'which is such that their tapersare opposite to each other.

The cone-pulleys 4 and 5 have convex pe ripheral bearing-surfaces 6 6,the adjacent sides of which, as seen in Fig. 1, have a substantiallyparallel direction and are spacedapart from each other,.so that there isafforded between such adjacent substantially parallel sides of thepulleys an opening the general direction of which is at an inclinationto the axes of the pulley-shafts 3 3 and wherein are adapted to bereceived certain intermediate parts, which will be hereinafter describedand which are capable of adjust- Y ment along said diagonal space in adirection.

parallel with the adjacent parallel sides of said pulleys.

7 indicates a narrow band or belt of annular or endless character, whichis passed around the peripheral bearing-surfaces 6 6 of the respectivecone-pulleys 4 and 5 and which has one of its runs, as shown at 8,extended directly at a. tangent from and be.- tween saidbearing-surfaces 6 6. In ordinary constructions of this type oftransmission apparatus each bight of said endless band or belt hasengagement around substantially one hundred and eighty degrees of thecircumference of each of the pulleys 4.- and 5, and by reason of suchlimited engagement of the band or belt with said pulleys a narrow bandor belt can be employed only Where comparatively light mechanisms are tobe driven from the transmission apparatus.

9 9 indicate parallel guide rods or bars which are extended diagonallybetween the frame parts 1 1 and along the space between the adjacentsides of the pulleys in directions parallel with said adjacent ulleyfaces or sides, the extremities of said guide rods or bars 9 9 beingheld in arms 10 10, oppositely directed from the frame parts 1 1, asseen in Fig. 2, and 11 indicates an auxiliary frame or carriage formedof connected spaced side ortions having perforated lugs 12 12 for sliing engagement and movement lengthwise upon the guide bars or rods 9 9,the side portions which the direct run or spaced from each other as toproduce between them a central opening 13, through side 8 of the band orbelt 7 is passed, as seen in Fig. 2.

The side portions of the auxiliary frame or carriage 11 have parallelundercut guideways 14 14, between which is held to slide in a directiontransverse to the length of the guide bars or rods 9 9 a bracket 15,having oppositely-arranged bearings wherein are held, as seen at 16, theends of a shaft or stud 17, on which the intermediate or shifting pulleyor sheave 18 is carried, said intermediate sheave or pulley having agrooved peripheral surface 20 of convex cross-section and of suflicientwidth to receive the belt or band 7 and having flanges 19 19 at oppositesides of said convex surface and provided with annular grooves orrecesses in their inner surfaces to provide guides for said band or belt7 and prevent the latter from slipping off laterally in passing aroundsaid intermediate pulley.

represents a lug formed 011 the auxiliary frame or carriage 11, and 26is a link, one end whereof is connected with said lug 25, while itsopposite end has connection, as seen at 27, with a lever 28, pivotallymounted, as seen at 29, upon a segment 30 on one of the frame portions 1and provided with a series of apertures 31 in concentric arrangementwith the pivotal point 29 of lever 28 and adapted to receive a pin orscrew 32, carried by said lever, for holding said lever 28 in adjustedposition upon the frame. hen said screw or pin 32.i s removed, lever 28may be swung pivotally, and its movement will be communicated, by meansof link 26, to the auxiliary frame or carriage 11, carrying theintermediate sheave or pulley 18, whereby said carriage and intermediatesheave or pulley will be moved in a path along the inclined guiderods 9and parallel with the inclinations of the peripheral bearing-faces 6 ofthe pulleys 4 and 5, the engagement of the undercut flanges 19 of saidsheave or pulley 18 with the narrow belt or band at its side or run 21opposite to the run 8, which passes direct between the pulley-faces,serving in such movement of the sheave or pulley 18 to move said band orbelt lengthwise along the pulleyfaces, so as to accomplish the desiredspeed variation, after which by again inserting the screw or pin 32 inthe appropriate aperture 31 of segment 30 the parts may be held againstaccidental movement from the de sired adjustment.

As herein shown, when the intermediate sheave or pulley 18 is adjustedso that its axis stands in the same plane with the axes of shafts 3 3,on which the conoidal pulleys 4 and 5 are held, whereby one side of therounded face 20 of said intermediate sheave or pulley is brought intoproximity with the run or side 8 of belt or band 7, which is passeddirectly between the bearing-faces 6 6 of pulleys 4 and 5, and the otherside or run 21 of the band or belt 7 is carried inwardly between thepulleys 4 and 5 and is. passed around the side of the intermediatesheave or pulley 18, which is adjacent to said direct run 8 of the beltor band, whereby, as shown in Fig. 2 of the drawings, the terminalbights of the belt or band, which are passed around the pulleys 4 and 5,are caused. to contact with a greater arc of each pulley-face than. ispossible where, as in ordinary forms of this type of transmissionapparatus, both sides or runs of the belt or band are passed directlyacross the space between the pulleys as is the side or run 8. By theparticular arrangement of the parts herein shown the belt or bandv hasdriving engagement upon the inner or adj acent parts of the taperedpulley-faces, so that instead of said belt or band having engagementaround only about one hundred and. eighty degrees of the driving-face ofeach pulley 4 and 5, as in ordinary constructions, the drivingengagement of the band or belt is extended and increased to coversubstantially two hundred and forty degrees of the peripheral face ofeach of said pulleys.

here a greater are of engagement of the band or belt with the pulleys 4and 5 is desired than is afforded by the construction above described,the arrangement shown in Fig. 4 may be employed. In this form thebracket 15 will be provided with. u )wardly and downwardly extended arms33, each of which carries a small pulley 34, grooved for engagement withthe belt 7, which is thereby caused to engage upon the pulleys 4 and 5around arcs much greater than in the construction shown in the otherfigures, the rear run of the belt being drawn up closely adjacent andparallel with the direct run or side 8.

In this class of transmission apparatus there has heretofore beenpresent a feature of great disadvantage, due to the creeping of the bandor belt endwise upon the pulleys, whereby the apparatus is renderedaltogether unfit for employment where accurate speed changes aredesirable. This creeping of the band or belt is due to the taper of thecone pulleys, which tend to impart two different speeds to the two edgesof the band or belt, and it will be obvious that the greater the widthof the band or belt the greater will be the difference in speed impartedat the two edges thereof, and consequently the greater will be thecreeping efiect produced thereby. Where narrow bands or belts areemployed, the creeping upon the pulleys is much less than in the case ofwider bands or belts; but it will be apparent that in ordinaryconstructions, where the bights of the band or belt are engaged aroundonly substantially half the perimeters of the cone-pulleys, theemployment of very narrow belts or bands is in most cases renderedimpossible on account of the reduced driving power afiorded thereby.

Where the cone-pulleys 4 and 5, as herein shown, have driving-surfaces,as at 6, the creeping of the band or belt upon the pulleys is reduced toa minimum or practically elimi nated where comparatively narrow bands orbelts are provided, and by the employment of the means comprising theintermediate sheave or pulley for increasing the arcs of engagement ofthe band or belt upon the driving and driven pulleys 4 and 5 it isevident that the narrow band or belt thus employed is given an increasedbearing upon the conepulleys, such as could otherwise be obtained onlyby increasing the width of the band or belt, the engagement of saidintermediate sheave or pulley 18 within the central bight 21 of saidband or belt serving to draw the run or side of the band or belt whereinsaid central loop or bight 21 is produced in between the pulleys 4 and5, so as to give the band or belt bearing on said pulleys around greaterand increased arcs, as seen at 22 in Fig. 2. l

As seen in Fig. 2, there is a toothed rackbar 35 extended across thespace between parts 1 1, parallel with the guide rods or bars 9 9, onwhich the frame or carriage 11 slides, the teeth of said rack-bar 35being in mesh with those of a pinion 36 moving in unison with thecarriage 11 and having a shaft or stud 37, on which is carried aneccentric 38, turning inside a strap or band, whereon is an arm 39,connected with the bracket 15, whereon the intermediate sheave or pulley18 is held to turn. The proportions of the parts may be so arranged thata full turn of the pinion 36 will be accomplished by each full movementof the carriage 11 from one side of the main frame to the other, and thearrangement of the eccentric 38 on shaft 37 will be such that theextreme throw of said eccen tric 38 will be accomplished at the centerof the extent of travel of the carriage 11, or opposite the centralpoint in the lengths of the cone-pulleys, whereby in the adjustment ofcarriage 11 from side to side of the main frame a tightening of the bandor belt will be gradually effected as the same is shifted toward acentral position with res ect to the pulley-faces, while as the band orelt is shifted away from a central position relative to the pulley-facessaid band or belt will be loosened, this tightening and loosening of theband or belt being automatically efiected by the transverse slidingmovement of bracket 15 across the path of the carriage 11.

The improved transmission apparatus constructed according to myinvention is of an extremely simple and inexpensive nature and isespecially desirable for use, since it permits of securing acomparatively great driving effect from a narrow band or belt, thedisadvantageous feature of creeping common in similar devices beingeliminated for all practical purposes.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. In combination with a pair of spaced pulleys, an endless band passedaround the same and having a portion thereof bent inwardly to extend insaid space, a sliding car.- riage, a bracket adjustable on the carriagea pulley carried on said bracket and enga ing said inbent band portion,an arm carrie by said bracket, an eccentric rotatably supported fromsaid arm, a stud carried by said eccentric, a pinion carried by saidstud, and a stationary rack-bar in mesh with said pinion.

2. In combination with a pair of spaced pulleys, an endless band passedtherearound and having a portion thereof bent inwardly to extend in saidspace, a sliding carriage, a bracket movable on said carriage, a pulleycarried by said bracket and engaging said inbent portion of the band,mechanism connected to said bracket for moving the latter transverse ofthe direction of movement of the carriage, and stationary means toengage said mechanism and operate the same when the carriage is moved.

3. In combination with a pair of spaced pulleys, an endless band passedtherearound and having a portion thereof bent inwardly to extend in saidspace, a sliding carriage, a bracket movable on the carriage a pulley onsaid bracket engaging said inbent portion of said band, arack, a pinionsupported from said bracket and engaging said rack, and means formounting said pinion whereby when said carria e is moved said bracketwill be moved therewlth and in addition in a plane transverse to that ofsaid carriage.

Signed at Cincinnati, Ohio, this 13th day of April, 1905.

ERNST RICHTER.

Witnesses:

JOHN ELIAS JoNEs, WILLIAM SCHUCHARDT.

